Justin Shuma

I recently purchased a 2018 gmc 2500 with the duramax. It has about 126,000 miles. After it sits for at least an hour there is a high pitched squeal around 35mph. It gets higher and lower when pressing or taking off the gas pedal. Video attached. It goes away after the first two miles or so. I have had two shops look at it and neither could figure out what it is. Won’t let me upload the full video. Link to it on YouTube here. IMG_8351.MOV